Printing instrumentalities for typewriting machines



F. H. TREGO 1,933,570

PRINTING INSTRUMENTALIT IES FOR TYPEWRITING M CHINES Nov. 7, 1933 FiledFeb. 4, 1931 5 Sheets-Sh eeti INVENTOR Fran/f H. 771990 W ATTORNEY L'NOV. 7, 1933. F1 H, TREGQ 7 1,933,570

PRINTING INSTRUMENTALITIES FOR TYPEWRITING MACHINES Filed Feb. 4, i951 5Sheets-Sheet 2 INVENTOR ,F/am/f H. 77690.

A'ITORNEY F. H. TREGO 1,933,570

PRINTLNG INSTRUMENTALITIES FOR TYPEWRITING MACHINES I Nov. 7, 1933.

Filed Feb. 4, 1931 5 Sheets-Sheet 3v F. H. TREGO Nov. 7, 1933.

PRINTING INSTRUMENTALITIES FOR TYPEWRITING MACHINES 5 Sheets-Sheet 4Filed Feb. 4, 1931 NOV. 7, 1933. TREGQ- 1,933,570

PRINTING INSTRUMENTALITIES FOR TYPEWRITING- MACHINES Filed Feb. 4. 19315 Sheets-Sheet S INVENTOR Fran/f H. 771. 90.

BY Q Z 4170mm? its Patented Nov. 7, 1933 UNITED STATES PRINTINGINSTRUMENTALITIE S FOR TYPEWRITING MACHINES Frank H. Trego, New York, N.Y., assignor, by mesne assignments, to Ralph C. Coxhead Corporation, NewYork, N. Y., a corporation of Delaware Application February 4, 1931.Serial No. 513,270

25 Claims.

This invention relates to printing instrumentalities for typewritingmachines and is in the nature of improvements which may be used withparts shown in my application, Serial No. 495,872, filed November 15,1930.

The invention is shown as applied to the machine known as the Varityperin which there is provided a type shuttle which may be rotated throughvarious angular distances, by the keylevers, to select the desired type,subsequent to which a hammer is operated to strike against the shuttleto print-on a work-sheet disposed between the shuttle and the hammer,and in which machine the carriage assists in restoring the hammer tonormal.

An object of the present invention is to facilitate the operation of themachine. To this end the printing hammer is restored to normal or cockedby an electro-magnet, and the printing operation of the hammer iseffected by a spring under the control of the keys.

A feature of the invention relates to means independent of the carriageand the escapement mechanism, whereby the hammer is held cocked againstthe action of its actuating spring.

Another feature of the invention relates to means under the control ofthe keys whereby the release of the hammer may be effected.

A further feature of the invention relates to means, including a switchoperable by the hammer, to effect the energization of the electromagnet,to thereby restore the printing hammer or, in other words, cock it.

Still another feature of the invention relates to means to delaydzheclosing of the switch. until the hammer has printed so as to prevent apremature return of the hammer. This means is also effective to ,delaythe opening of the switch so as to insure cocking of the hammer beforethe electro-magnet, which returns the hammer, is de-energized.

Other features and advantages will hereinafter appear.

In the drawings which form part of the specification,

Fig. 1 is a sectional side view of the machine;

Fig. 2 is a sectional top plan view of a portion of the machine taken onthe line 2-2 of Fig. 1;

Fig. 3 is a rear view of the machine;

Fig. 4 is a skeleton side view showing the hammer printing, and theactuation of the switch initiated and about to be completed by thedeclosed;

Fig. 6 is a rear view showing the dog-rocker of the escapement mechanismoperated and the hammer about to be released; and

Fig. 7 is a view similar to Fig. 6 but showing the loose dog and thehammer operated.

Similarreference characters represent similar parts throughout theseveral views.

The machine includes a main frame provided with tracks 22 upon whichis'supported a carriage 23, to travel back and forth, through the 55medium of anti-friction balls or rollers 24. The carriage is providedwith feed rollers 25 and 26 by which a work-sheet 26 may be fed upwardlybetween a type carrier or shuttle 2'7 and a hammer 28, the latter beinglocated behind the work- 7 sheet.

The type shuttle 27 is located in front of the work sheet and issupported on an anvil 30 secured to a shaft 31 suitably supported by acrossbar 32-and a plate 33 on the machine frame. 7-5 The shuttle 2'7 isactuated by a lever 34 connected to said shuttle by an upwardlyextending finger 35 engaging a fin 36 which extends through a slot 37 inthe anvil 30, the fin serving also tosupport the shuttle on the anvil.

The shuttle actuating lever 34 is secured to a sleeve 38 rotatably'supported on the shaft 31 and bearing on the cross bar.32. Said levermay be actuated in opposite directions about the axis of the shaft 31 inthe usual manner by. means including two universal bars 40, one beingassociated with the set of key-levers 41 to the righthand side of themachine, the other (not shown) being associated with the set ofkey-levers to the left-hand side of the machine. Each universal bar isoperable by its associated key-levers to actuate a frame 41, of whichthe universal bar forms a part, about a fulcrum 42to swing an upwardlyextending arm 43 rearwardly to actuate the shuttle lever 34; a returnspring 44 being 95 provided for the universal bar.

To assist in registering the selected types at the printing point,indexing devices or stops 5! are associated with the key-levers 41,- andactuable thereby against the action of return springs 51, to project theupper ends of the stops into the path of an arm 52 of theshuttleactuating lever 34, said lever when actuated striking theoperated stop to arrest the type shuttle, with the selected type at theprinting point.

The carriage 23 is connected by the usual rack 55 with a pinion 56 ofthe carriage escapement 57 which is actuable by a universal bar 58. Theuniversal bar 58 is engageable by the rear ends of the key levers 41 andforms part of a frame 59 actuable about pivots 60 to swing downwardly arearwardly extending arm 61 which operates a dog-rocker 62 (Fig. 3)about its pivot 63 to carry a fixed dog 64 into the path of the teeth 65of an escapement wheel 66 secured-to a shaft 67'; the escapement wheel66 having the usual one-way driving connection, with the carriage,including a spring-pressed pawl 68 (Fig. 2) on a disk 69 and a ratchet70; the carriage being urged leftwardly by a spring drum 71 (Fig. 2)which is connected to the carriage 23 by a strap 72.

After the dog 64 has moved into the path of the teeth 65 of theescapement wheel, a loose dog 75 is swung about its pivot 76 out ofengagement with the escapement wheel (see Fig. 6) by an arm 77 having aslot 78 into which extends a pin 79 from said loose dog. Upon therelease of the loose dog it is carried upwardly as in Fig. 7 by a frame80 pivotally supported on the escapement shaft 67, said frame beingactuated by a spring 81. The pawl 75, as it is carried upwardly, isguided into the path of the next adjacent tooth of the escapement wheel,by the inclined slot 78, so that upon the subsequent release of theescapement wheel from the dog 64, the escapement wheel rotates and thusreturns the loose dog to normal, thus effecting a single letter feedingmovement of the carriage.

The hammer 28 (Figs. 1 and 2) is secured to a shaft supported on themain frame 20 by pivot screws 86. It is held cocked against the actionof a spring 87 by a pawl 88 (Fig. 3) engaging a projection 89 on thehammer. Upon the release of the hammer from said pawl 88, in a mannerhereinafter described, the spring 87 actuates it about the pivots 86 tostrike against the shuttle 27.

In order to disengage the pawl 88 from the projection 89, when thehammer is to be operated, there is provided on the arm 61, of theescapement operating frame 59, an extension 90 which, upon the actuationof any one of the key levers 41, pulls downwardly a link 91 connected toan arm 92 secured to a shaft 93; the shaft 93 being supported on abracket 94 secured to the main frame 20. The shaft 93 has securedthereto another arm 95 which is actuated, in a clockwise direction inFig. 3, to swing the holding pawl 88 about its pivot 96, through themedium of an actuating pawl 97, pivotally supported on said arm 95, by astud 98, as in Fig. 6, to release the hammer 28. Instantly after therelease of the hammer from the pawl 88 the latter becomes released fromthe actuating pawl 97 and is snapped back to normal position by a spring99, as in Fig. 7, where the pawl 88 is arrested against the hammerprojection 89.

The release of the pawl 88 from the actuating pawl 97 is effected sothat the pawl 88 may be in readiness to lock the hammer in its normalorcocked position should the hammer be restored (as hereinafter described)before the actuating pawl 97, since the return of the latter may bedelayed by a slow removal of the finger from the depressed key lever.The actuating pawl 97 in returning to re-engage the holding pawl, mayyield against the action of a spring 99 to snap behind a tooth 100 ofthe pawl 88. The spring 99 tends to hold the actuating pawl against astop 101 by which its movement is limited relatively to the supportingarm 95.

The effective length of the link 91 may be varied to effect properco-operation of the actuating pawl 97 with the holding pawl 88. To thisend there are provided nuts 102 and 103 threaded on the link 91 andwhereby the point of connection of said link with the extension 90 maybe adjusted.

The hammer is returned or cooked, against the action of its spring 87,by an electro-magnet or solenoid 105, the coil 106 of which may beconnected to a source of power by a manually controlled switch 107 sothat when a switch 108 (Fig. 1) is closed by the hammer, as hereinafterdescribed, an electric circuit is completed including a conductor 109,extending from the source of power, switch 107, coil 106, conductor 110,fixed contact 111 and movable contact 112 of switch 108, and conductor113 which is also connected with the source of electric energy.

Upon the closing of the switch 108, which occurs after printing, thecoil 106 is energized and it sucks in a plunger 114 to return the hammerfrom the position in Fig. 4 to the position in Fig. 1.

The connection between the plunger 114 and the hammer includes a lever116, having a pinand-slot connection 117, 118 with the plunger 114,whereby said plunger may actuate said lever about a stud 119 on a fixedbracket 120 which may be secured to a flux frame 121 of the solenoid.The lever 116 draws forwardly a link 122 connected to an arm 123 securedto the hammer supporting shaft 85 to thus rock the latter and therebyreturn the hammer to normal where, it will be remembered, the latch 88engages the extension 89 to hold the hammer against the action of thespring 87.

The switch 108 includes an actuable element 125 pivotally supported by astud 126 upon a fixed bracket 127, and has mounted thereon, but suitablyinsulated therefrom, the switch contact 112. While the hammer is movingto its printing position an extension 128 thereon engages an arm 129 .tooperate the element 125 about its pivot to initiate the closingoperation'of the switch 108.

To guard against a premature return of the hammer 28, or, in otherwords, insure printing thereof, before the solenoid is energized toreturn said hammer, the operation of the switch or controlling means 108is retarded so that, although its operation has been started by thehammer, it is not completed until after the printing has occurred. Forthis purpose the arm 129 is pivotally supported, by means of a stud 130,on the actuable element 125 of the switch; said arm 129 being actuable,when engaged by the hammer extension 128, about the pivot 130 andagainst the action oi a spring 131, the actuation of the element 125being resisted by a weight 132 and a detent spring 133 having a roller133 engaging one side of a nose 134 formed on the element 125. While thespring 131 recovers and overcomes the inertia of the weight 132. theelement 125 is further rotated thereby. about its pivot 126 (Fi 4) tomove the nose 134 to the lower side of the roller 133 whereupon thedetent. becomes effective to continue the actuation of the element 125and thus close the switch, as in Fig. 5, where the hammer is printingand is just about to be restored to normal by the solenoid which, itwill be remembered, is energized by the closing of the switch 108.

Similarly, provision is made todelay the opening of the switch orcontrolling means 108 so as to insure latching of the hammer, againstthe action of its spring 87, before the solenoid is de-energized. As thehammer 28 returns, the extension 128 thereof actuates an arm 137 about apivot 138 and against the action of the spring 131 to overcome theinertia of the weight 132. The return movement of the actuable element125 is thus initiated while the latching ofthe hammer is taking place,and when the latter has been accomplished the detent 133, 133 acts tocomplete the action of the switch element 125 and thus open the switchto de-energize the solenoid 105. The contact 112 of the switch 108 issupported by a resilient member 139 so that the switch 108 may be keptclosed for a time during the initial movement of the element 125 to opensaid switch.

The arms 129 and 137 are provided with set screws 140 and 141,respectively, whereby the points of contact of the arms 129 and 137 maybe adjusted relatively to the hammer extension 128 to assist in timingthe operation of the switch.

The spring 131 is connected between the arms 129 and 137 and tends todraw their operable ends towards each other. They are arrested, however,by stops 142 and 143 on the actuable element 125. The movement of saidactuable element 125 may be limited in both directions by stops 144 and145 on the bracket 127.

While certain preferred embodiments of the invention have been shown, itshould be understood that changes in the form, arrangements,proportions, sizes and details thereof may be made without departingfrom the scope of the invention as defined in the appended claims.

I claim:

1. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key-levers, a spring, means operable by said key-leversto render the spring eiTective to actuate one of said elements towardsthe other toprint, an electro-magnet and means operable by thekey-levers whereby the electro-magnet is rendered efiective to returnthe operated one of said printing elements to normal against the actionof said spring.

2. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key-levers, a spring under the control of said key-leversto actuate one of said elements towards the other to print, anelectro-magnet to return the actuable element, an electric circuit forsaid electro-magnet, and a normally open switch in said circuit operableby the actuable element to close said switch to energize theelectro-magnet to return the operable element.

3. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key levers, a spring under the control of said key-leversto actuate one of said elements towards the other to print, anelectromagnet to return the actuable element, an electric circuit forsaid electro-magnet, a normally open switch in said circuit operable bythe actuable element to close said switch to energize ments towards theother to print, an electromagnet to return the actuable element, anelectric circuit for said electro-magnet, a normally open switch in saidcircuit'operable by the actuable element to close said switch toenergize the electro-magnet to return the operable element, meansoperable by the actuable element to initiate the closing operation ofthe switch, and means to complete the closing operation of the switch.

5. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key-levers, a spring under the control of said key-leversto actuate one of said elements towards the other to print, anelectro-magnet to return the actuable element, 'an electric circuit forsaid electro-magnet, a normally open switch in said circuit operable bythe actuable element to close said switch to energize the electro-magnetto return the operablev element, means operable by the actuable elementto retard the closing of the switch to insure printing by the twoco-operating elements before the return of the actuable element isefiected.

6. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key-levers, a spring under the control of said key-leversto actuate one of said elements towards the other to print, anelectromagnet to return the actuable element, an electric circuit forsaid electro-niagnet, a normally open switch in said circuit operable bythe actuable element to close said switch to energize the electro-magnetto return the operable element, said switch being operable by and uponthe return stroke of the actuable element, and a latch whereby theactuable element may be locked in its returned position before theswitch is completely opened.

7. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key-levers, a spring under the control of said key-leversto actuate one of said elements towards the other to print, anelectro-magnet to return the actuable element, an electric-circuit forsaid electro-magnet, a normally open switch in said circuit operable bythe actuable element to close said switch to energize the electromagnetto return the operable element, switch actuating means operable by theactuable ele-- ment, and means to further actuate the switch actuatingmeans to thereby open the switch after the actuable element has beencompletely restored.

8. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid said elements, key-levers, a spring under the control of said keylevers to actuate one of said elements towards the other to print, anelectromagnet to return the actuable element, an electric circuit forsaid electro-magnet, a normally open switch in said circuit operable bythe actuable element to close said switch to energize the electro-magnetto return the actuable element, switch actuating means operable by theactuable element to start the closing operation of said switch, and adevice to further operate theswitch actuating means to close the switchto efiect energization'of the electromagnet after printing to restorethe actuable element, and a latch to lock the actuable element in itsreturned position, said switch actuating means being'also operable bythe actuable element during the initial part of its return movement,said device being effective to further actuate the switch actuatingmeans to open said switch, after the actuable element has been latched,to de-energize the electro-magnet.

9. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key-levers, means under the control of said key-levers toactuate one of said elements to effect printing, an electro-magnet,means operable by the electro-magnet to restore the actuable element, anelectric circuit for said electro-magnet, said switch including amovablev member, means associated with said movable member tending toretard its operation, resilient means operable by the actuable elementto initiate the operation of said movable element, and means to completethe operation of the movable member to close said switch, and thuseffect energization of the electro-magnet to restore the hammer.

10. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, whereby. the printing may be effected, an electro-magnetconnected to actuate one of said elements, an electric circuit for saidelectromagnet, a switch in said circuit whereby the electrical conditionof said electro-magnet may be altered, resilient means operable by theactuable element to initiate the operation of said switch, means toretard the operation of said switch, and means to complete the operationof said switch after the complete operation of the actuable element.

11. In a typewriting machine, the combination of printinginstrumentalities including a hammer, a spring to actuate said hammer,means to restore said hammer, a latch to hold said hammer in normalposition, key levers, a universal bar operable by said key-levers, meansoperable by the universal bar to actuate said latch to release saidhammer, the latch actuating means when actuated through a predetermineddistance disengaging the latch, and means to restore the latch aftersuch disengagement so as to be ready to engage the hammer when, thelatter is returned to normal.

12. In a typewriting machine, the combination of printinginstrumentalities including a hammer, a spring to actuate said hammer,means to restore said hammer, a latch to hold said hammer in normalposition, key levers, a universal bar operable by said key-levers, meansoperable by the universal bar to actuate said latch to release saidhammer, the last named means disengaging the latch when actuated througha predetermined distance, and means to restore the latch so as to beready to engage the hammer when the latter is returned to normal, the,latch releasing means including a yieldable element to permitreengagement of the latch releasing means with said latch.

13. In a typewriting machine, the combination of two co-operatingelements, namely, a hammer and an anvil, a type shuttle associated withsaid elements, key-levers, means under the control of said key-levers toactuate one of said elementsclosing of the switch until the printing hasbeen effected.

14. In a typewriting machine, the combination of a carriage, carriagepropelling means, printing instrumentalities including two co-operatingelements, namely a stationary element and an actuable element,key-levers, a type carrier between the two co-operating elements, meansoperable by the key-levers to effect the setting of the type carrier,power'means, means operable by the key-levers to render said powermeanseffective to actuate the operable element of the printinginstrumentalities, an electro-magnet, an electric circuit for saidelectro-magnet, a normally open switch in said circuit, and meansoperable by said key-levers to effect the closing of said switch, saidelectro-magnet being also effective to energize the power means for theactuable element of the printing instrumentalities while said operableelement is being returned to normal.

15. In a typewriting machine, the combination of printinginstrumentalities including two cooperating elements, namely astationary element and an actuable element, key-levers, a settable typecarrier between said co-operating elements, means operable by thekey-levers to set the type carrier, power means, means operable by thekey-levers to render said power means effective to operate said actuableelement, an electromagnet, an electric circuit for the electro-magnet, anormally open switch in said circuit, means operable by said key-leversto initiate the closing of said switch, and means to retard the closingof the switch so as to insure printing before the solenoid becomeseffective to return said actuable element.

16. In a typewriting machine, the combination of means including aselectively settable type carrier, a hammer to co-operate therewith,keylevers, power means to actuate the hammer, means operable by thekey-levers to-render the power means effective, an electro-magnet toreturn said hammer to normal, an electric circuit for theelectro-magnet, a normally open switch in said circuit, and means toeffect the closing of said switch to energize the electro-magnet toreturn said hammer.

17. In a typewriting machine, the combination of means including aselectively settable type carrier, a hammer to co-operate therewith,key-. levers, power means to actuate the hammer, means operable by thekey-levers to render the power means effective, an electro-magnet toreturn said hammer to normal, an electric circuit for theelectro-magnet, a normally open switch in said circuit, means to effectthe closing of said switch to return the hammer by said electromagnet,and means to delay the closing of the switch to insure printing of saidhammer before the solenoid starts to return it. I

18. In a typewriting machine, the combination of printinginstrumentalities including two cooperating elements, namely astationary element and an actuable element, key-levers, a type carrierbetween the co-operating elements, means operable by the key-levers toeffect the setting of the type carrier, power means to operate saidactuable element, means operable by the keylevers to render the powermeans effective, electrically operated means to return the actuableelement to normal, means to effect the operation of the electricallyoperated means, and means to delay the operation of the electricallyoperated means until the printing operation is completed.

19. In a typewriting machine, the combination of. printinginstrumentalities including two co-operating elements, namely astationary element and an actuable element, key-levers, a type carrierbetween the co-operating elements, means operable by the key-levers toeffect the setting of the type carrier, power means to operate saidactuable element, means operable by the keylevers to render the powermeans efiective, electrically operatedmeans to return the actuableelement to normal, controlling means for the electrically operated meansby which it may be rendered ineifective, means to initiate the operationof the controlling means, and means to delay the operation of thecontrolling means so as to insure the complete return movement of theactuable element by the electrically operated means before it isrendered ineffective.

2D. In a typewriting machine, the combination of printinginstrumentalities including two co-operating elements, namely astationary 'element and an actuable element, a selectively settable typecarrier between the co-operating elements, power means to operate saidactuable element, means to render the power means effective, power meansincluding a solenoid to return the actuable element to normal,controlling means for the solenoid, said controlling means beingoperable by the actuable element on its effective movement to render thesolenoid effective to return the actuable element, said controllingmeans being operable by the actuable element on its return stroke torender the solenoid ineffective, and means to retard the operation ofthe controlling means so that the actuable element may be completelyreturned before the solenoid is rendered effective and to insure thecomplete return of the actuable element before the solenoid is renderedinefiective.

21. In a typewriting machine, the combination of printinginstrumentalities including two co-operating elements, namely astationary element and an actuable element, a selectively settable typecarrier between the co-operating elements, a spring to operate saidactuable element, a latch to normally hold the actuable element againstthe action of said spring, means to release the actuable element fromthe latch, an electrically operated device to return said actuableelement to normal, controlling means for said electrically opera-teddevice, means to actuate the controlling means to render saidelectrically operated device elf-active and ineffective, and meansco-operating with the controlling means whereby the-electricallyoperated device is maintained effective until theactuable element hasbeen returned to the latch against the action of said spring.

22. In a typewriting machine, the combination of printinginstrumentalities including two co-operating elements, namely astationary element and an actuable element, a selectively settable typecarrier associated with said elements, power meansv to operate saidactuable element, means to render the power means efiective, an electricdevice to return the actuable element, a pivoted switch element torender the device efiective and inefiective, a stop for the switchelement, a detent to hold the switch element against said stop, and aresilient device operable by said actuable element to start the closingoperation of said switch element and to gradually overcome the holdingaction of the detent, the latter becoming finally effective to completethe operation of the switch element to close it after the printingoperation and thus effect the operation of the electric device to returnthe actuable element.

23. In a typewriting machine, the combination of printinginstrumentalities including two co-operating elements, namely astationary element and an actuable element, a selectively settable typecarrier associated with said elements, power means to operate'saidactuable element, means to render the power means efiective, an electricdevice to return the actuable element, a pivoted switch element torender the device effective and ineifective, means to actuate saidswitch to render the electric device eifective to return the actuableelement to normal against the action of thepower means, means to holdthe actuable element in its returned position, resilient means operableby the actuable element to start the opening operation of the switchelement, and a detent tending to retard the operation of said switch soas to insure the return of the actuable element to the holding meansbefore the switch is opened, the resilient device being I efiective togradually overcome the retarding action of said detent, the latterbecoming finally effective to open said switch to render the electricdevice ineffective.

24. In a typewriting machine, the combinaco-operating elements, namely astationary element and an actuable element, a selectively set table typecarrier associated with said elements,

tion of printing instrumentalities including two power means to operatethe actuable element in one direction, an electric device 'to'operatethe actuable elementin the opposite direction, a pivoted switch for saidelectric device, resilient means operable by the actuable element tostart the operation of said switch, means tending to retard theoperation of said switch to insure the completion of the operation ofthe actuable element before it is operated in theopposite direction, theretarding means becoming finally efiective to complete the operation ofsaid switch.

25. In a typewriting machine, the combination of printinginstrumentalities including two co-operating elements, namely astationary 'ele-' ment and an actuable element, a selectively settabletype carrier associated with said elements, power means to operate theactuable element in one direction, an electric device to operate the'actuable device in the opposite direction, a piv-

